Furnace mechanism and process for bloating clay



March 22, 1932. E. M. WYATT ET AL 1,850,221

FURNACE MECHANISM AND PRCCESS FOR BLOATING CLAY Filed Oct. 7, 1929 2Sheets-Sheet l March 22, 1932. E. M. WYATT ET AL 1,850,221

FURNACE MECHANISM AND PROCESS FOR BLOATING CLAY a 4 Z 2 6W a v 7 W ,w ww 2 J @R a w Filed Oct. 7, 1929 Patented 22, 1932 UNITED STATES PATENTOFFICE EDWIN I. WYATT, OF CLEVELAND, OHIO, AND HOWARD F. WEISS, OFMADISON, WISCONSIN, ASSIGNORS, BY MESNE ASSIGNMENTS, TO AMERICAN FACEBRICK RESEARCH CORPORATION, A CORPORATION OF ILLINOIS FURNACE.MECHANISMAND PROCESS FOR FLOATING CLAY Application filed October 7, 1929. SerialNo. 398,066.

This invention relates to improvements in furnace mechanism and processfor bloating clay, in the manufacture of bloated clay products of thecharacter described and claimed in co-pending application Serial No.382,358, filed July 31, 1929, cellular building material.

The object of the invention is to provide furnace mechanism adapted tocontinuously feed the raw argillaceous materials in the form of granularparticles and in such a way as to form a continuous slab or columnsuitable for cutting into building units or other about 1800 F.; (2) todeposit it on a conveyor that carries it through a furnace chamber at ahigher temperature, about 2100 .F., where the heat sears over the top ofthe deposited clay and forms a rubbery skin thereon; (3) to turn thematerial over the end of the conveyor to bring it other side up on a bedof sand or similar material that keeps the now sticky clay from adheringto the furnace; (at) to move the material through another furnacechamber in this inverted position until the newly exposed surface isskimmed over and the interior of the mass bloats and coheres into a slabor column; to pass the material into a chamber of lower temperaturewhere it cools and anneals; and,

(6) finally to pass itout of the furnace where the column or slab is cutinto the desired articles of commerce. 7

These operations will be better understood by study ofthe accompanyingdrawings, wherein,

Figure 1 is a vertical section on the longitudinal center line, markedAA in Figures 2, 3. and 4;

Fig. 2 is a double vertical cross section, the

along left half being on the line BB of 1 and 3, the right half being onthe line CC of Figures 1, 3 and 4;

Fig. 3 is a double plan or horizontal section. the upper half being on aline DD, and the lower half on line EE of Figure 1 Fig. 4 is ahorizontal section taken on the line FF of Figures land 2;

Fig. 5 is a section on the line GG of Figure 1 Fig. 6 is 'a topperspective view of a brick cut from a bloated clay slab;

Fig. 7 is a bottom perspective view of a brick out from a bloated clayslab;

Figs. 8, 9 and 10 are diagrammatic views showmg modifications in theconveyormeans employed for feeding the granular material and invertingit as it passes from the upper lciiamber of the furnace to the lowerchamr The same identifying numerals refer to the same parts in alldrawings.

The travel of the clay through the furnace can be followed entirelythrough on Figure 1, though reference to other drawings will makeclearer the shape of the furnace involved. The clay to be bloated,marked 1, comes into the furnace from the right through a standard typerotary ln'ln, the shell of which is marked 2 and the refractory inside3. Within the rotary kiln, the material in granular form is preheatedand subjected to agitation to secure uniformity in the penetration ofthe heat.

From the rotary kiln thev clay pours out through a transfer chamber i(shown equally well in Figures 1, 2 and 3) on to an inclined vibratingplate conveyor of which 5 is the deck and sides, and 6 are supportingand stiffening members. (Figures 2 and 5 show the construction of thisconveyor best).

The vibration of the conveyor moves the clay under a strike of! 7, thatlevels the material to a uniformdepth and carries it the bottom of acombustion chamber 8 unti it works off the lower end of the con veyorover a refractory cylinder 9, which, revolved by the weight of thematerial and the pressure exerted by the clay being pushed off of theconveyor, carries the material.

parts fromheat that about half way around the c linder and deposits itother side up on a e'd of sand 10 deposited on a refractory slab 11,which is upwardly curved at its receiving end.

Here the clay is subjected on top to the heat from the furnace chamber12, called the bloating chamber, and from underneath enetrates thesupporting slab 11 from the urnace chamber 13. From the bloating chamberthe material passes through the opening 15 in the furnace wall into theannealing chamber 18, which is heated to a lower temperature adequate toanneal the slab and toughen it.

From the annealing oven, the bloated clay slab, now toughened andcooled, passes to the endless belt. or late conveyor 20 supported onconveyor w eels 21. As the. conve or bears the slab from the annealingcham r.

it carries it under saws or abrasive cutting disks 22 that slit the slabby the kerfs 24 into strips 25. Also while on the conveyor, a crosscutting disk 26 cuts the strips into smaller units 27.

The movement ofthe column of bloated clay is caused first by vity as theclay descends 'around the cy inder 9 and down the inclined portion ofthe slab 11, and sec-.

0nd by ull exerted by certain synchronized power-( iven moving parts,namely, the top and bottom compression rolls 16 and 17, the carryingrolls 19, and the conveyor 20.

To keep the sticky fused cla from adhering to the floors and walls 0 thefurnace, sand or other loose refractory material that will put withinitself when its outer particles are adhered to is fed in between theclay and the furnace. This sand is first fed in from side hoppers 29(see Figs. 2 and 4) through the ducts 30 (Figs. 2, 3 and 4) where itflows under the strike ofi 7 in beside the clay in marginal streams ofrectanular cross section 10 (Figs 2, 3 and 5).

t maintains this position while flowin around the cylinder 9, as shownat 10 0 Fig. 3, but after passing the cylinder where the marginalstreams are no longer restrained on their outward sides, they fall intothe angle of repose on that side, so that each stream then assumesapproximately the'crom section of a right angle triangle (see 10' Figs.2 and 3).

Sand or its equivalent is also fed into the furnace from the hopper 31(Figs. 1 and 3) so that it rolls across the refractory slab 32 (Figs.1,2, and 3) where it is heated in transit' and then falls on top of thesticky top surface of the clay comin down the conveyor and over thecylin er at the point vmarked 33 on Fig. 1. From there on this surfacebecomes the bottom surface of the column, and the layer of sand keepsthe sticky bloating clay on top of it from adhering to the floor hearth.As the bloated clay enters the annealing chamber, the clay her 12through the side ducts 35, and with the chamber 8 through side ducts 36.'I The cham-. bers 12 and 8 are connected through ducts 37. The chamber8 connects with the rotary kiln through the transfer chamber 4. Theburned gases are finally discharged through a stack at the outer end ofthe rotary kiln, which parts, bein of conventional type, are not shownin the rawin s.

The crank 39 fastene to the cylinder 9 is to partially control the flowof clay through the application of accelerating or retarding ressure,especially when starting the manuacturing operation. The space 40 (Figs.1 and 2) 1s but partiall enc osed and conseuently somew at coo ed byoutside air, so t at the conveyor 5- will be so that the clay directlyin contact with it will not become sticky and cling to it.

y In Fig. 6 is shown a finished brick 27 as it would appear when outfrom the slab by the ept cool enough out faces are those that in a wallare in con- I tact with the mortar. In Fig. 7, the same cut surfacesshow and in addition the surface that in the slab was in contact withthe sand 44. Some of the sand 45 is seen adhering to the brick.

Where it is desired that the completed units have a more level topsurface than that given by the compression roller 16, the surface isground by grinding wheels mounted on the shafts that carry either thecutting disks 22 or 26,- or on a special shaft built for that pur- Thesevariations are not shown in the rawings.

Thou h sand has been mentioned throughout as t e material to be used tokeep the bloating clay from sticking to the furnace parts, it is to beunderstood that other materials, such as talc and mica, can be used inplace of sand as parting media.

It should be understood that all of these drawings are more or lessschematic, and are to be broadly interpreted as to details, and that inpractice many variations may be made in the details shown. To illustratesome of such variations, Figs. 8, 9 and 10 show modifications from theconveyor shown in Figs. 1, 2 and 3. Fi 8, 9 and are abbreviated sectionsma e on the same plane as Fig. 1, AA but show different types ofconveyors. 5 In Fig. 8, the vibrating conveyor of previous drawings isreplaced by an endless belt or plate conveyor, of which 5 is a belt orchain of plates, and 6 are the pulleys carrying the belt. y

In Fig. 9, the conveyor is shown as a refractory slab 5 with a lip 6"that turns down and takes the place of the cylinler 9 of Fig. 1. Thisrefractory slab is vibrated, not with a. back and forth vibration as inthe type shown in Fig. 1, but with a four-way circular vibratorymovement that causes the material in the throat to move downward underthe action of the lip as does the conveyor of Fig. 8, or the cylinder ofFig. 1.

In Fig. 10, the vibrating conveyor is replaced by a stationary incline 5and 6 pitched at slightly less than the angle of repose of the hot clay.The cylinder 9 is mechanically fed at a uniform speed that constantlyfeeds the clay through the throat and keeps the clay moving down theincline by undermining that supported by the incline.

The material in granular form will be thoroughly dried and preheated asit feeds 80 down the incline of the rotary kiln, and at the same time,during this stage, certain of the more explosive gas formingconstituents will be driven off, so that as the material passes from therotary kiln it will be in suitable :5 condition to enter the zones ofhigher tem-' perature within which the material becomes fused andtheparticles coalesce together and are bloated-by the formation within themass of minute cells, separated and defined by cell an walls ofvitrified material, giving to the mass as a whole the cellular characterof baked bread. v

The descending mass engages the strikeofi' 7 at a time when it is stillin the granular 4: or non-coalescent form, so that it will be leveleddown to a uniform thickness before 'the surface begins to fuse, whichoccurs within the chamber 8, so that during the progress of the massthrough this chamber it will -u begin to assume the character of acoalescing or continuous mass, although at this stage the heat will notpenetrate sufliciently to the interior of the mass to cause completefusion within the interior.

As the coalescing mass, which now begins to assume the characterof acontinuous slab,

passes over the roller 9, it will be inverted, so

that the previously formed surface skin will now be presented at thebottom of the mass and rest upon the sand which is spread upon thecurved refractoryslab 11 to prevent adhesion. This inversion of thecolumn brings the previously unexposed surface upwardly and subjects itto the intense heat within the lower chamber 12, so that at this stage,a surface skin will rapidly formv and the heat will penetrate to theinterior, so that the bloating will continue in increasing degree as thenow I full coalescing column progresses through the lower chamber, withthe result that during this stage of the operation a continuous andcoherent column will evolve, which is capable of being drawn forward bythe action of the rollers 16 and 17 within the annealing chamber 18.

As shown in Fig. 1, the upper roller 16 not only serves as a feedingelement but also tends to press down or smooth ,down the upper surfaceof the fused and now somewhat plastic mass, but if it is desired toretain the surface in its natural or undeformed and ebbled condition,the roller means 16 may provided which merely engage the margins of theslab and do not exert a positive compressive contact with the exposedsurface. It will be understood, however, that other feeding devices ofany suitable character may be employed'in lieu of therollers, which areadequate to grip or engage the column and exert the necessary pull ortension thereon to draw the same through the furnace.

It will thus be observed that during the initial stage formation andwhile the mass IS in a granular and noncoherent condition, the feedingwill be effected by gravity or by vibration, but that thereafter, as thematerial progressively coalesces into a continuous column possessingtensile strength, the feeding will be effected by draw rollers orsimilar means adapted to draw the continuous slab forward. V

The invention is one in which the parts are so related that the heatedgases flow from the zone of the highest temperature in up- 105 warddirection and in opposition to the direction of movement of. thematerial, so that the cooling gases are utilized in full within theupper heat zones where a maximum temperature is not desirable, and arefinally discharged through the rotary kiln and into the stack, therebyconserving the heat units to the fullest possible extent.

The invention is one which serves to produce a product of substantiallyhomogeneous 115 or uniform character, by reason of the inversion of theslab which permits the heat to penetrate uniforml to the interior and atthe same time resu ts in the formation of a slab which is provided witha continuous skin on both of its surfaces.

011a fused skin upon the exposed surface of the layer, inverting thelayer of material and exposing the prevlously unexposed granularsurface, and subjectingthe inverted material to a temperature and for atime adequate to cause fusion and bloating of the mass into the form ofa continuous slab.

- zone of 2. The process of bloating earthy materiali which consists infeeding granular'materia in the form of a continuous layer through aheat zone and subjecting it to a temperature adequate to cause theformation of a continuous fused skin upon the exposed surface, in-

verting the layer of 'material to expose the previousl unexposed surfacewithin a heat igher temperature, tofirst cause formation of a surfaceskin on the surface thus e osed, and to finally cause bloating of theentire mass and the formatiqn of a continuous slab.

3. The process of bloating earthy material, a

which consists in feeding granular material in the form of a continuouslayer through a heat zone and subjecting it to a temperature adequatetocause the formation of a continu ous fused skin upon the exposedsurface, in-v verting the layer of material to expose the previouslunexposed surface within a heat zone of formation of a surface skin onthe surface thus ex sed, and to finally cause bloating of the entlremass and the formation of a continuous slab, and drawing thecontinuously formed slab forwardly and out of the heat zone. e

4. The process of bloating earthy material,

which consists in feeding granularmaterial in the form of a continuouslayer through a heat zone and sub'ecting it to a temperature adequate tocause he formation of a continu-' tinuous slab, and drawing thecontinuouslyformed slab forward and out of the heat zone. and sub'ectingthe continuously formed bloated slab to an annealing temperature.

- 5. The process of bloating earthy material. which consists in feedinggranular material in the form of a continuous layer through 'a' heatzone and subjecting it to a temperature adequate to cause the formationof a continuous fused skin upon the exposed surface, in

verting the layer of material to expose the previously unexposed surfacewithin a heat zone of higher temperature, to first cause formation of asurface skin on the surface this exposed, and to finally cause bloatingof the entire mass and the formation of a continuous slab, and drawingthe continuously formed slab forwardly and out of the heat ighertemperature, to first causezone, and subjecting the continuously formedbloated slab to an annealing temperature, and finally severing theslabinto building units of the desired dimensions.

6. The process'of bloating earthy material, which consists in firstsubjecting granular material to a preheatin spreading the preheatematerial while in granular condit1on in the form of a layer of uniformthickness and in advancin the layer of material through a heat zone 0%temperature adequate to fuse the exposed surface and form a continuousskin thereover, next in inverting the skinned-over layer and introducingthe layer other side up into a heat zone having a temperature adequateto first form a skin over the newly exposed surface and thereafter bloatthe interior of the mass to form a continuous slab of, cellularmaterial.

7 The process of bloating earthy material, which consists in firstsubjecting granular material to a preheati temperature, then spreadingthe preheate material I While in granular condition in the form of alayer of uniform thickness and in advaincin the layer of materialthrough a heat zone 0 temperature adequate to fuse the exposed surfaceand form a continuous skin thereover, next in invertin the skinned overlayer and in troducing e layer other side up into a heat zone having atem erature adequate to first form a skin over t e newly exposed surfaceand thereafter bloat the interior of the mass to form a continuous slabof cellular material, and in continuously drawin said bloated slabtemperature, then through the last mentione heat zone under tension. 7 4v 8. The process of bloating earthy-material, which consists in firstsubjecting granular material to a preheatin spreading the reheatematerial while 1n granular condition in the form of a layer of uniformthickness and in advancin the layer ofvmaterial through a heat zone oftemperature adequate to fuse the exposed surface andform a continuousskin thereover,-next in invertin'g the skinned over layer and introducmgthe layer other side up into'aheat zone a temperature adequate to firstform a skin over the newly exposed surface and thereafter bloat theinterior of the. mass to form a continuous slab of cellular material,and in continuously draw said bloated slab through the last mentioneheat zone under tension, and in continuously delivering said :lab to azone heatedtc an annealing tempera 9. The process of bloatin earthymaterial," which consists in first su jectinggranular material to apreheating temperature, then spreading the preheated material while ingranularfcondition in the form of 'a'layer of temperature, thenform acontinuous slrin thereover, next in inverting the skinnegt 'over layerand introand cutting it into building units of the desired dimensions.

10. The process of bloating earthy material, which consists in firstsubjecting granular' material to a preheating temperatureunderconditions of agitation, then spreading the preheated materialwhile "in granular condition in the form of a layer of uniform thicknessand in advancing the layer of material through a heat zone 'oftemperature adequate to fuse the exposed surface and form a continuousskin thereover, next in inverting the skinned over layer and introducingthe layer other side up into a heat zone having a temperature adequateto first form a skin 'over the newly exposed surface and. thereafterbloat the interior of the mass to form a continuous slab of cellularmaterial,

and in continuously drawing said bloated slab through the last mentionedheat zone under tension, and in continuously delivering said slab to azone heated .to an annealing temperature, and finallv in continuouslydischarging the slab from the annealing zone and cutting it into.building units of thedesired dimenslons. r

11. In furnace mechanism of the class described, the combination of afurnace partitio'ned to provide an .upper chamber and a lower chamber incommunication with one another, an inclined conveyor within the up perchamber, and a refractory slab within the lower chamber, the parts beingso related that a layer-0f material passing down the-conveyor in theupper chamber willpass on to the slab in the lower chamber in invertedposition, and means adapted to exert tension for withdrawing thematerial, when in the form of a coherent bloated slab, from the lowerchamber.

' 12. In furnace mechanism of the class described, the combination of afurnace partitioned to provide an upper chamber and a lower vchamber incommunication with one another, an inclined conveyor within the upperchamber, and a refractory slab within the lower chamber, the parts beingso related that a laver of material passing down the conveyor in theupper chamber will pass on to the slab in the lower chamber in invertedposition, and

means forwithdrawing the material, when in the form of a coherentbloated slab, from the lower chamber, and a preheater located above c vthe conveyor and adapted to discharge matei-f rial in granular form onto the conveyor.

13. In furnace mechanism of the class described, the combination of afurnace partitioned to provide an upper chamber and a. lower chamber incommunication with one another, an inclined conveyor within the upperchamber, and a refractory slab within the lower chamber, the parts beingso; related that a layer of material passing down the conveyor in theupper chamber will pass on tothe slab in the lower chamber ininvertediposition, and means for withdrawing the material, when in theform of a coherent .bloatedslab, from the lower chamber, and a preheaterlocated above conveyor and adapted to discharge material point ofcommunication with the lower chamber, a supporting surface within thelower 0 chamber extending reversely with respect to the line of movementeffected by the conveyor in the upper chamber, and adaptedto receive thelayer of material from the upper chamber in inverted position to presentthe hitherto unexposed surface to the heat of the lower chamber.

15. In furnace mechanism of the class described, the combination of afurnace provid-v ed with an interior-partition dividing the furnace intoan upper chamber and a lower chamber, in communication with one another,a conveyor within the upper chamber, adapted to continuously carryforward a layer of material through the upper chamber to the a lowerpoint of communication with the lower cham-..v her, a supporting surfacewithin the lower,

chamber extending reversely with respect to the line of movementeffected by the conveyor in the upper chambergandadapted to receive thelayer of material from the upper chamber r in inverted position topresent the hitherto exposed surface to the heat of the lower chamher,and roller means located at the foot of the conveyor and in proximity tothe supporting surface in the lower chamber, and adapted to feed thelayer of material past the angle between the conveyor and the supportingsurface. 16. In furnace mechanism of the class described, thecomhination'of a furnace provided with an interior partition dividingthe furnace into an upper chamber and a lower chamber, in communicationwith one another, a conveyor within the upper chamber, adapt- 1 materialthrough the upper chamber to the ed to continuously carry forward alayer of a 5 lower chamber extending reversely with respect to the lineof movement effected by the conveyor in the upper chamber, and adapted.to receive the layer of'material from the upper chamber in invertedposition to resent the hitherto unexposed surface to the eat of thelower chamber, and roller means located at the foot of the conveyor andin proximity to the supporting surface in the lower chamber, and a aptedto feed the layer of material past the angle between the conveyor andthe supporting surface, and pullin means positioned to engage thematerial w en bloated to the form of a continuous slab within the lowerchamber and to withdraw it therefrom.

17. In furnace mechanism of the class described, the combination of afurnace provided with an interior partition dividing the furnace into anupper chamber and a lower chamber, in communication with one another, aconveyor within the upper chamber, adapted to continuously carry forwarda layer of material through the upper chamber to the point ofcommunication with the lower chamber, a supporting surface within thelower chamber extending reversely with respect -to the line of movementeffected by the conveyor in the upper chamber, and

adapted 'to receive the layer of material from p the upper chamber ininverted position to present the hitherto'unexposed. surface to the heatof the lower chamber, and roller meaiis located at the foot of theconveyor and in proximity to the support' surface in a the lowerchamber, and adapte to feed the layer of material past the angle betweenthe conveyor and the supporting surface, pulling means itioned to engagethe material when bloa to the form of a continuous slab within the lowerchamber and to, withdraw it therefrom, and an annealing chambercommunicating with the lower chamber and in 'tion to receive the slab ofmaterial withi wn therefrom. a

'18. In furnace mechanism .of the class described, the combination of afurnace provided with an interior partition dividing the furnace into anupper chamber and a lower chamber, in' communication with one another, aconveyor within the upper chamber, adapted tocontinuously carry forwarda layer of int of communication with the lower chamr, a supportingsurface within the lower chamber extending reversely with respect to theline of inovementelfected by the conveyor in the upper chamber, andadapted to receive the layer of material from the upper .chamher ininverted position to present the hitherto unexposed surface to the heatof the lower chamber, roller means located at the foot of the conveyorand in proximity to the supporting surface in the lower chamber, andadapted to feed the layer of material past the angle between theconveyor and the support ing surface, pullin means positioned to engagethe material w en bloated to the form of a continuous slab within the loer chamber and to withdraw it therefrom, and an anneal ing chambercommunicating with the lower chamber and in position to receive the slabof material withdrawn therefrom, and cutting devices located at thedischarge end of the annealin chamber for severing the material intounits of the desired size.

19. In furnace mechanism of the class described, the combination of afurnace provided with an upper chamber and a lower chamber, incommunication with one another. a rotary reheater discharging into theupper cham' er of the furnace, an inclined conveyor leading through theupper chamber from the discharge end of the reheater to the point ofcommunication with the lower chamber, and a slab within the lowerchamber extending therethrough in divergent relation with respect to theconveyor in the upper chamber and curvedly upturned at its conver g endto receive the layer of ma-.

terial m the conveyor and invert the same to bring the previouslyunexposed surface upwardly within the lower chamber.

20. In furnace mechanism of the class described, the combination of afurnace provided with an upper chamber and a lower chamber, incommunication with one another, a rotary reheater discharging into theupper chamber of the furnace, an inclined conveyor leading through theupper chamber from the discharge end of the preheater. to the point ofcommunication with the lower chamber, a strike o'fi located above theconveyor in spaced relation thereto and adapted to level down thematerial to the form or a layer of uniform thickness, and a slab withinthe lower chamber extending therethrough in divergent relation withrespect to the con- .veyor in the upper chamber, and curvedly chamber ofthe furnace, an inclined conveyor leading through the upper chamber fromthe discharge end of the preheater to the point of communication withthe lower chamber, a slab within the lower chamberextending therethroughin divergent relation with respect to the conveyor in the upper chamberand curvedly upturned at its converging end to receive the layer ofmaterial from the conveyor and. invert the same to bring the previouslyunexposed surface upwardly within the lowerchamber, and a rollerinterposed between the lower endof the conveyor and the proximate end ofsaid slab, and adapted I a rotary preheater discharging into the up perchamber of the furnace, an inclined conveyor leading through the upperchamber from the discharge end of the preheater to the point ofcommunication with the lower chamber, a strike off located above theconveyor in spaced relation thereto and adapted to level down thematerial to the form of a layer of uniform thickness, a slab within thelayer of material from the conveyor and invert the same to bring thepreviously unexposed surface upwardly within the lower chamber, and aroller interposed between the lower end of the conveyor and theproximate end of said slab, and adapted to underlie the oncoming layerof material and assist in reversing'its direction of movement and ininverting it to bring the previously unexposed surface upwardly withinthe lower chamber.

23. In furnace mechanism of the'c'lass described, the combination of afurnace provided with an 'upper chamber and a lower chamber, incommunication with one another, a rotary preheater discharging into theupper chamber of the furnace, an inclined conveyor leading through theupper chamber from the discharge end of the preheater to the point ofcommunication with the lower chamher,'a slab within the lower chamberextending therethrough in divergent relation with respect to theconveyor in the upper chamber and curvedly upturned at its convergingend to receive ,the layer of material from the conveyor and invert thesame to bring the precontinuous slab and to withdraw the same from thechamber. 7 i l 24.] In furnace mechanism of the class described, thecombination of a furnace provided with an upper chamber and a lowerchamber, in communication with one another,

a rotary preheater discharging into the upper a chamber of the furnace,an inclined conveyor leading through the upper chamber from thedischarge end of the preheater to the point of communication with thelower chamber, a strike 011' located above the conveyor in spacedrelation thereto and adapted to level down the material to the form of alayer of vimiform thickness, a slab within the lower chamber extendingtherethrough in divergent relation with respect to the conveyor'in theupper chamber, and curvedly upturned at its converging end to receivethe layer of material from the conveyor and invert the same to bring thepreviously unexposed surface up-.

wardly within the lower chamber, a roller 1nterposed between the lowerend of the conveyor and the proximate end of said slab,-and adapted tounderlie the oncoming layer of material and assist in reversing itsdirection of movement and in inverting it to bring the previouslyunexposed surface upwardly within the lower chamber, and roller meansadapt-- ed to engage the material when formed into a continuous slab and-to withdraw the same from the chamber.

25. In furnace mechanism of the class described, the combination of afurnace provided withan upper chamber and a lower chamber, incommunication with one another,

a rotary preheater discharging into the upper 1 chamber of the furnace,an inclined conveyor leading through the upper chamber from thedischarge end of the preheater to the point of communication with'thelower chamber, a

slab within the lower chamber extending therethrough indivergentrelationwwith respect to the conveyor in the upper' chamber andcurvedly upturned at its converging .end to receive the layer ofmaterial fromthe conveyor and invert the same to bring thepreviouslyunexposed surface upwardly within the lower Chamber, a rollerinterposed between the lower end of the conveyor and 'the proximate endof the slab, and adapted to underlie the oncoming layer of material andassist in per chamber of the furnace, an inclined conveyor leadinthrough the upper chamber from the disc ar e end of the preheater to thepoint of communication with the lower chamber, a strike ofi locatedabove the conveyor in spaced relation thereto and adapted to level downthe material to the form of a layer of uniform thickness, a slab withinthe lower chamber extending therethrough in divergent relation withrespect to the conveyor in the upper chamber, and curvedly upturned atits convergin end to receive the layer of material from t e conveyor andinvert the same to bring the previously unexposed surface upwardlywithin the, lower chamber, a roller interposed between the lower end ofthe conveyor and the proximate end of said slab, and adapted to underliethe oncoming layer of material and assist in reversing its direction ofmovement and in inverting it to bring the reviously unexposed surface upwardly within the lower chamber, and a chute for delivering material toprevent adhesion and located to discharge such material in in terposedrelation between the layer of granular material and the slab in thelower chamber.,

27 In furnace mechanism of the class described, the combination of afurnace pro vided with an upper chamber and a lower chamber, incommunication with one another, a rotary preheater discharging into theupper chamber of the furnace, an inclined conveyor leading through theupper chamber from the discharge end of the preheater to the point ofcommunication with the lower chamber, a slab within the lower chamberextending therethrough in divergent relation with respect to theconveyor in the upper chamber and curvedly u turned at its convergingend to receive the ayer of material from the conveyor and invert thesame to brin the previously unexposed surface upward l y within thelower chamber, a roller interposed between the lower end of the conveyorand the proximate end of the slab, and adapted to underlie the oncominglayer of material and assist in reversin its direction of movement andin inverting it to brin the previously-unexposed surface upwar 1y withinthe lower chamber, and a chute for delivering material to preventadhesion and located to discharge such material in interposed relationbetween the layer of granular material and the slab in the lowerchamber, and means for discharging marginal streams of material upon theconveyor along the edges of the granular material discharged thereonto.

28. In furnace mechanism of the class described, the combination of afurnace provided with an upper chamber and a lower chamber, incommunication with one another, a rotary preheater discharging into theupper chamber of the furnace, an inclined conveyor leading through theupper chamber from the discharge end of the preheater to the point ofcommunication with the lower chamber, a strike off located above theconveyor in spaced relation thereto and adapted to level down thematerial to the form of a layer of uniform thickness, a slab within thelower chamber extending therethrough in divergent relation with r to theconveyor in the upper chamber and curvedly upturned at its convergingend to receive the layer of material from the con- 'veyor and invert thesame to brin the previously unexposed surface upwar y within the lowerchamber, a chute for delivering material to prevent adhesion and locatedto discharge such material in interposed relation between the layer ofgranular material and the slab in the lower chamber, and means fordischarging marginal streams of material upon the conveyor along theedges at its convergin end to receive the layer of material from t econveyor and invert the same to brindg the previously une sed surfaceupwar y within the lower 0 amber, a roller interposed between the lowerend of the conveyor and the proximate end of the slab, and adapted tounderlie the oncoming layer of material and assist in reversin itsdirection of movement and in inverting it to brin the previouslyunexposed surface upward y within the lower chamber, and a chute" fordelivering material to prevent adhesion and located to discharge suchmaterial in interposed relation between the layer of granular materialand the slab in the lower chamber, and roller means located beyond thelower chamber and adapted to engage the continuous bloated slab formedtherein and to continuously withdraw the same therefrom.

30. In furnace mechanism of the class described, the combination of afurnace provided with an upper chamber and a lower chamber, incommunication with one another, a rotary preheater discharging into theupper chamber of the furnace, an inclined conveyor leading through theupper chamber from the discharge end of the preheater to the point ofcommunication with the lower chamber, a strike ofi located above theconveyor in spaced relation thereto and adapted to level down. thematerial to the form of. a layer of uniform thickness, a slab within thelower chamber extending therethrough in divergent relation with respectto the conveyor in the upper chamber, and curvedly upturned at itsconverging end to receive the layer of material from the conveyor andinvert the same to brin the previously unexposed surface upwar ly withinthe lower chamber, a roller interposed between the lower end of theconveyor and the proximate end of said slab, and adapted to underlie theoncoming layer of material and assist in reversing its direction ofmovement and in inverting it to bring the previously unexposed surfaceupwardly within the lower chamber, a chute for delivering material toprevent adhesion and located to discharge such material in interposedrelation between the layer of granular material and the slab in thelower chamber, and roller means located beyond the lower chamber andadapted to engage the, continuous bloated slab formed therein and tocontinuously withdraw the same therefrom.

31. In furnace mechanism of the class described, the combination of afurnace provided with an upper chamber and a lower chamber, incommunication with one another, a rotary preheater discharging into theupper chamber of the furnace, an inclined conveyor leading through theupper chamher from the discharge end of the preheater to the point ofcommunication with the lower chamber, a slab within the lower chamberextending therethrough in divergent relation with respect to theconveyor in the upper chamber and curvedly upturned at its convergin endto receive the layer .of material from t e conveyor and invert the sameto bring the previously unexposed surface upwardly within the lowerchamber, a roller interposed between the lower end of the conveyor andthe proximate end of the slab, and adapted to underlie the oncominglayer of material and assist in reversing its direction of movement andin inverting it to bring the previously unexposed surface u wardlywithin the lower chamber, and a c ute for delivering material to preventadhesion and located to discharge such material in interposed relationbetween the layer of granular material and the slab in the lowerchamber, and means for discharging marginal streams of material u on theconveyor along the edges of the granufdr material discharged thereonto,and roller means located beyond the lower chamber and adapted to engagethe continuous bloated slab formed therein and to continuously withdrawthe same therefrom.

32. In furnace mechanism of the class described, the combination of afurnace provided with an upper chamber and a lower chamber, incommunication with one another, a rotary preheater discharging into theupper chamber of the furnace, an inclined conveyor leading throu h theupper chamber from the discharge en of the preheater to the point ofcommunication with the lower chamber, a strike off located above theconveyor in spaced relation thereto and adapted to level down thematerial to the form of a layer of uniform thickness, a slab within thelower chamber extending therethrough in divergent relation with respectto theconveyor in the upper chamber and curved] upturned continuousbloated slab formed therein and tfzo continuously withdraw the samethererom.

In witness that we claim the foregoing, we have hereunto subscribed ournames this 19th day of September, 1929, and this 23rd day of September,respectivel v ED IN M. WYATT.

HOWARD F. WEISS.

